it depends on a number of factors
It is too broad of a question. Key elements to take into account in your analysis are: Costs (Yen or £), NGO or UN (very different), personal preferences of the person managing the procurement process, quantity purchased, funding sources (eg tied assistance or not), expected purpose and use, expected duration (projects vs regular operations), availability or not at any given time, exchange rate and others. There are also obvious geographical disparities, for example you'll hardly find Land Rovers in Egypt, plenty of defenders in Kenya, Jeep Cherokee in Haiti, Land Cruiser Prado in many West African countries, Pajero in Asia, etc. The development assistance world is a universe in itself, it seems risky to generalize, but indeed a good source of inspiration to find out what lasts! I always smile seeing those Peugeot 504 Station Wagon rolling still, those cars were tough!